Godan verb with 'ku' ending, Intransitive verb
to be surprised; to be taken aback; to be amazed; to be astonished; to be shocked
知事は委員会の反応に驚いた。The governor was surprised by the commission's response. to be frightened; to be startled; to be alarmed
Also written 愕く【おどろく】、駭く【おどろく】